The goal is to get to a desirable population destination before tragedy overtakes us.
Humankind has contracting supporting resources (e.g. fossil fuels, soils, fisheries and minerals.)
So the question remains, what process do we put in place to:
b) once we arrive at this new population,
Some rule like “less than two” or “one” is not a very good plan.
We all understand how hard it would be to get any number like 2 or 1 births-per-woman to be part of our culture. However, few of us have given consideration as to how hard it would be to undo it once the sustainable population was reached in 2100.
We need a process, for reducing population very quickly, that after it reaches its 50-100 million goal the process maintains that population.
A process that uses true fertility rate (number of children per woman) to achieve its stable population is not prudent. Whatever TFR was low enough to help make birth choices on the steep population down slope would leave residue in the birth decision process, that would wipe out the remaining 50-100 million people.
Our process has to be a bit more sophisticated than that. I have proposed a lottery to allow a fixed number of births each year during both the steep decline and the maintence time periods.I have outlined the mathematics of such a lottery in SKIL Note 81.
SKIL Note 81 ==> Today's "Dropping Fertility" is Meaningless and Harmful in Establishing Sustainability. It is futile to adjust human nature up or down on number of children. Let civil law determine the population that is sustainable.
Of course I do not want to minimize the difficulty of implementing such a lottery.